Fixed timestep for some GUI & input code

Fixed timestep only applied to the physics simulation, but input and GUI updates were not being handled properly, so here's some progress into fixing them.

Subsurface/Source/Items/Components/ItemComponent.cs

@@ -469,6 +469,8 @@ namespace Barotrauma.Items.Components
         //}
 
         public virtual void DrawHUD(SpriteBatch spriteBatch, Character character) { }
+
+        public virtual void UpdateHUD(Character character) { }
         
         /// <returns>true if the operation was completed</returns>
         public virtual bool AIOperate(float deltaTime, Character character, AIObjectiveOperateItem objective)